1. Field of the Invention
The invention concerns a device for delivering a pasty stuffing material in portions, for example in the production of sausage by filling the stuffing material into hose-shaped skins or guts prepared and held ready for this purpose, the device comprising conveying means for charging the stuffing material with pressure in order to convey it into a filling pipe via an outlet channel, as well as shut-off (sealing) and controlling means being arranged in the region of the outlet channel for influencing and controlling the flow of the stuffing material and including a vane rotor extending through the cross-section of the outlet channel, the pressurized stuffing or filling material being conveyed through said outlet channel via shut-off and controlling means into said filling pipe.
2. Description of Prior Art
In a known device of this type (see German Offenlegungsschrift No. 32 46 421) a volumetric measuring device is provided which comprises a vane rotor extending over the cross-section of the filling pipe and driven by the flow of the stuffing material. The change of the angle of rotation of the vane rotor is controlled by means of a measuring device. The vane rotor is further provided with a braking device acting thereupon and controlled by the measuring device so that the described device forms a combined closing and measuring apparatus, the latter serving for determining and controlling the portioning volume.
Practice has shown it is necessary to allow an undesirably high pressure to act on the stuffing material in the operation of this device, in particular in order to safeguard a sufficient filling and portioning velocity. The necessary pressure of the stuffing material is essentially higher in this process than would be necessary for the filling process as such even in the case of a high filling speed.
These circumstances show decisively disadvantageous consequences. In particular, in the case of critical stuffing material there is an increased tendency of the material to segregate, whereas, altogether, there is a significant tendency towards quality reduction, e.g. by increased leakage on sliding sealing surfaces. Moreover, the requirement of high pressure is accompanied by important and essential requirements with regard to the filling accuracy and precision, in particular of the moving elements and the stability of the structural elements, which, on the other hand, necessitates an undesirably high expenditure in construction, manufacture and costs. Finally it should be noted that energy consumption is correspondingly higher. A further disadvantage lies in the fact that due to the high compression of the stuffing material after the closing of the sealing (shutoff) element upon reaching the desired portioning volume a corresponding expansion occurs which has the effect of an exceedingly high follow-on (trailing) flow of stuffing material. The known device does not show any possibility of compensating for this disadvantage.
A device which serves this purpose is known from German Offenlegungsschrift No. 21 37 278. This device comprises a rotary disc valve as sealing element, which has an offset portion on its side facing the free end of the filling pipe, which offset portion forms a suction chamber in the closing position. The volume of the suction chamber can be influenced by a variable stop so that the rate of re-suction can be adjusted.
Normally such a sealing element is used in portioning devices whose basic structure can e.g. be taken from European Patent Publication No. 61 995. In such devices a volumetric measuring device is provided which effects a control of the sealing (shutoff) element independent of the measuring and which in this case serves to enable a direct control of the passage of the stuffing material to be portioned. However, the above mentioned disadvantages resulting essentially from the necessary high conveying pressure are also inherent in this embodiment of the volumetric measuring device which is structured as a passively driven vane rotor. Moreover, there is the disadvantage that such shut-off or sealing elements stress the stuffing material in an undesirable manner either by shearing due to the change in the cross-section of the outlet channel during the activation or due to gap flow in particular shortly before the completion of the closing action or at the beginning of the opening of the closing element.
A further possibility of using the closing or sealing element according to German Offenlegungsschrift No. 21 37 278 is, according to the background of that publication, its application as a shutoff device of filling machines by means of which hose or gut sections are filled for producing sausages, these sausages being supplied to the consumer as a whole or in cut-off portions by weight, i.e. after dosage upon request by the consumer.
Finally mention is made of German Pat. No. 937 561 which shows a device for the metered delivery of granular bulk material and is based on the function of a metering star feeder. This known device, which is used for producing a defined mixing ratio or for controlling a certain flow rate includes an additional cellular wheel element which can be activated separately by switching and with the aid of which a mixing component having an adjustable portion of the intended mixture can be added.
This device, however, does not enable the delivery of a filling material against a pressure potential resulting e.g. from flow resistance. This structure is also not appropriate for producing small portions of high accuracy with regard to their weight and/or volume at a high frequency of portions.
3. Objects of the Invention
It is therefore an essential object of the present invention to suggest a device of the type described in the paragraph "Field of the Invention" which enables a careful and yet accurate delivery and filling with regard to weight and/or volume of any desired size of portion into hose-shaped foils (films) or guts held ready for this purpose.
It is a further object of the invention to enable such filling at high frequency or rate.
It still another important object of the invention to combine such a device with a sealing or clipping apparatus for such objects in an easy manner enabling the clearance of a defined length of the hose or gut e.g. for fixing two seals or clips behind one another.